USIM_DATA has internal pull-up inside the module, and external pull-up can be
reserved to keep NC. The recommended model for RV1 to RV5 is
EGA10402V05A2.
For SIM card slot with no card detection, the USIM_PRESENCE pin of the module
is suspended or connected in series with 10K resistor to ground.
The hot plug function is disabled by software default.
PCB Design
Layout key points:
⚫ Reserve capacitor filter for SIM signal line to prevent interference from high frequency
signal.
⚫ SIM card and routing should be away from EMI interference source, such as power circuit,
RF circuit, antenna, and high-speed digital signal circuit.
⚫ ESD components of SIM card should be close to SIM card slot interface.
⚫ When routing antenna feeder line, please keep the line away from power device, and avoid
the line paralleling to antenna copper foil.
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